BarinkOS/src/kernel/boot.S
2021-11-16 21:17:49 +01:00

78 lines
1.4 KiB
ArmAsm

/*
* Multiboot
*/
.set ALIGN, 1<<0 /* align loaded modules on page boundaries */
.set MEMINFO, 1<<1 /* provide memory map */
.set FLAGS, ALIGN | MEMINFO /* this is the Multiboot 'flag' field */
.set MAGIC, 0x1BADB002 /* 'magic number' lets bootloader find the header */
.set CHECKSUM, -(MAGIC + FLAGS) /* checksum of above, to prove we are multiboot */
.section .multiboot
.align 4
.long MAGIC
.long FLAGS
.long CHECKSUM
.section .bss
.align 16
stack_bottom:
.skip 16384 # 16 KiB
stack_top:
.section .text
.include "./src/kernel/irs_table.s"
.include "./src/kernel/irq_table.s"
.include "./src/kernel/idt/idt.s"
.include "./src/kernel/paging.s"
.global _start
.type _start, @function
_start:
/*Setup the stack pointer to point to the beginning of our stack */
/* I believe its a high address growing down to lower adress for the stack on x86*/
mov $stack_top, %esp
/*Reset EFLAGS*/
pushl $0
popf
/* push the pointer to the Multiboot information structure*/
pushl %ebx
/* push the magic value */
pushl %eax
call early_main
cli
.include "./src/kernel/gdt/gdt.s"
loadIDT:
#load idt
call init_idt
sti
# Try enable A20
# mov $0x2401, %ax
# int $0x15
# enable protected mode
mov %cr0, %eax
or $1, %eax
mov %eax, %cr0
call kernel_main
cli
1: hlt
jmp 1b
.size _start, . - _start